systematic characterization & evaluation of grid-connected ... · presentation overview...

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Systematic Characterization & Evaluation of Grid-connected

Flow Battery Systems

Bert Taube*, Randell Johnson**, Paul Leufkens, and Alyssa McQuilling

*Environment & Energy, Southern Research, Birmingham, AL, United States

**Acelerex, Boston, MA

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Presentation Overview

5/19/2020

• Background and Motivation• Energy Storage Deployment Risks• Overview of Southern Research Energy

Storage Research Center Facility (ESRC)

• Test Approach at the ESRC • Initial Results and Future Activities• Conclusions

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Background

5/19/2020

• Energy storage deployments in the US projected to grow exponentially in the future

• Recent developments in flow battery technologies enabled their grid deployment by improving energy density and reducing cost

• They are known for their long cycle life and slow degradation, as well as their high safety level

• Special strengths for energy-driven applications, especially for 4+ h functions

• Flow batteries particularly appealing due to their relatively simple construction with limited moving parts, not requiring high temperatures, and “no morphological changes that limit cycle life and depth of discharge [1]”

[1] M. Skyllas‐Kazacos, M. Chakrrabarti, S. Hajimolana, F. Mjalli, and M. Saleem, “Progress in Flow Battery Research and Development,” J. Electrochem. Soc. Crit. Rev. Electrochem. Solid‐State Sci. Technol., vol. 158, no. 8, pp. R55–R79, Feb. 2011.

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Overview of Flow Batteries• Flow batteries convert the

chemical energy in the electro-active materials directly to electrical energy

• The electro-active materials in a flow battery are stored in an electrolyte and are introduced into the device only during operation

• Systems where electro-active materials are dissolved in a liquid electrolyte are called redox (for reduction/oxidation) flow batteries

Flow Battery Diagram

5/19/2020

B. Garg, “Introduction to Flow Batteries: Theory and Applications,” 22-Mar-2012. [Online]. Available: http://large.stanford.edu/courses/2011/ph240/garg1/. [Accessed: 12-Jun-2019]

T. Nguyen and R. F. Savinell, “Flow Batteries,” Electrochem. Soc. Interface, vol. 19, no. 3, pp. 54–56, Jan. 2010

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MA6 I don't know if this slide is necessary; could easily be removed, but since the session is "energy storage implementation" i thought a brief overview of the technology might be reasonableMcQuilling, Alyssa, 6/13/2019

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• Safety and Environmental Risk refers to the potential for exposures to hazards associated with energy storage system• Potential for spillage, chemical release, or fire

Safety, Security, and Environmental Risks

Operational and Maintenance Risks

• Technology risk reflects the potential that a technology is not capable of providing expected services• Issues with lack of standardized controls; limited system

functionality

Technology and Design Risks

• Economic and regulatory risk reflects the extent to which a project is exposed to market and/or regulatory changes• Potential for modifications to existing rate structure

Economic and Regulatory Risks

Understanding and Mitigating Energy Storage Deployment Risks

5/19/2020 Southern Research Engineering

•Economic and regulatory risk reflects the extent to which a project is exposed to market and/or regulatory changes

•Potential for modifications to existing rate structure

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MA7 Electrochemical energy storage is a relatively new solution to a number of problems faced by the modern power grid. A few of the risks associated with energy storage deployment are highlighted here. In order to mitigate these risks, comprehensive testing and evaluation of energy storage systems, and in this case, flow batteries is critical.McQuilling, Alyssa, 6/13/2019

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Motivation for Systematic Characterization and Evaluation of Grid‐connected Flow

Battery Systems


The evaluation of flow batteries, particularly related to their ability to perform particular applications and perform

multiple services (i.e. value stacking) will be critical to support the development and adoption of flow batteries as a competitive option for grid-scale energy storage.

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MA8 To summarize, it's really important to characterize your ESS to make sure it's going to function as expected and provide the value it should.McQuilling, Alyssa, 6/13/2019

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Energy Storage Research Center at Southern Research


ESRC

The ESRC is highly collaborative andbuilds on partnerships between utilities,vendors, academia, and government.

Testing services at the ESRC areaugmented by research services, gridmodeling, and data analytics powered bythe Acelerex software architecture. Thesystematic evaluation of ESSs here isdesigned to mitigate risks associated withdeployment.

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MA9 The Energy Storage Research Center is a grid-scale energy storage testing center designed to meet the needs of a range of stakeholders from utilities to vendors. The site is currently installing its first test system, an Avalon flow battery system, and the following slides will detail the test approach, initial results and future plans for the system.McQuilling, Alyssa, 6/13/2019

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ESRC Testing Approach


Factory Acceptance Testing (FAT)

Commissioning

Baseline Functional and Performance Characterization

Use Case Testing

Advanced Testing and Modeling

The ESRC is involved at multiple stages of the evaluation of flow batteries including:

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Document Title Year Description

Test Protocols for Advanced Inverter Interoperability

Functions

November 2013

Test protocols to independently verify an inverter is properly executing advanced functions.

Protocol for UniformlyMeasuring and Expressing the

Performance of Energy Storage Systems

April 2016

Best practices for characterizing energy storage systems and measuring their performance relative to use case applications.

Energy Storage Integration Council (ESIC) Energy Storage

Test Manual

December 2017

Detailed test procedures for energy storage performance specification verification.

Energy Storage System Testing Protocols


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MA5 Testing programs at the ESRC for function, performance and use case testing are informed by previous testing guidelines and protocolspublished by EPRI and Sandia/PNNLMcQuilling, Alyssa, 6/12/2019

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Safety, Security, & Environmental• Engineering Documentation and Project

Planning

Performance & Operation• Characterization Testing• Use-case Validation

Degradation & Remaining Useful Life• Capacity Fade• Power Fade• Change in Self-Discharge Rate

Characterization of flow batteries at the ESRC will involve the following phases:

0• Preliminary Engineering Designs• Permitting

1• Manufacturing• Site Engineering

2• System Control Integration• Site Acceptance

3• Performance Characterization• Functional Characterization

4• Duty Cycle Testing

5• Autonomous Functionality

6• Modeling and Analysis

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Advanced Testing at the ESRC

• Understanding a system’s ability to perform multiple functions within a single day or simultaneously is critical to the evaluation of an ESS’s economic feasibility

• The ESRC, includes a software-hardware infrastructure that can enable this kind of testing

• Additionally, infrastructure supports the modeling of aging and performance over time for grid-scale flow batteries

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ESRC Flow Battery Evaluation Program


• The ESRC is currently beginning its testing program for an Avalon vanadium redox flow battery.

• The system being installed onsite includes 9 batteries in an array of the Avalon AFB2.10

• The system total power is 90 kW with a nominal capacity of 270 kWh

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• The Factory Acceptance Test (FAT) for the Avalon Flow battery system included the following components of testing: – Visual inspection of all system components– Basic 10 kW DC testing of 3 of 9 of the batteries involved in the system including:

• one time charging, sustaining and one time discharging and sustaining, observing temperature limits and SOC range

• basic functioning of the BMS, temperature sensors, pumps, and fans are evaluated• a short demonstration of charge and discharge at full rated power (Attention is focused on the

beginning and end of discharging).

– AC testing of a 3 battery string including one time charging, sustaining and one time discharging and sustaining; this functional test confirms the interaction of the inverter/PCS, DC batteries and EMS.

– Post‐DC and AC testing visual inspection to ensure there are no changes in the battery status or cleanliness (of particular concern would be any electrolyte residue that was not previously present).

FAT Overview for the Avalon BESS


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1. Installation Validation2. Post-Delivery Inspection & Testing3. System Specification Verification

Site Acceptance Testing Stages


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• The Avalon system is being grid connected• After installation and connection:

– SAT / commissioning– Monthly reference performance testing– Additional testing will be completed, including

• Baseline characterization• Functional Evaluation• Use case and stacked services testing

Next Steps for the Avalon BESS


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Conclusions

5/19/2020

• Energy storage is being deployed more frequently to meet a range of grid needs.

• Flow batteries will play an important role in meeting grid demands, especially Energy functions

• The ESRC offers a unique set of capabilities to fully evaluate the function and performance of flow battery systems

• The ESRC is currently hosting an Avalon BESS and will begin its comprehensive evaluation in collaboration with key utility, industry and academic partners.

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